You should see a rheumatologist. They'll do bloodwork and be able to tell you if you have psoriatic arthritis or something else like rheumatoid arthritis. Sounds like you might have PA.

I’ve started seeing a rheumatologist since being diagnosed with the PsA. They have me on Humira Snd methotrexate and I would suggest watching your diet. There are foods they consider ‘night shades’ that should be avoided. Plus of course all the good tasting food isn’t really good for you to eat and the gluten issues with done people, it totally stinks having to deal with this damn autoimmune crap.

I am also 55 & have had psoriasis & pa also , life is not too good at the moment , all the above symptoms ,I had Togo on the sick for couple of months to try & get it all together , been very stressed of late , must try to be stress free very difficult xxx

I have both psoriatic arthritis and psoriasis. I may have had it prior to my mother passing, but at any rate, that is when it blew up and I had to take notice. I was 55. I now have an excellent rheumatologist, dermatologist, and medical doctor who have worked together trying to get everything under control.
Fatigue, joint swelling, and blood work confirmed the PA. It's horrible and stress does make it worse. But how do we live a stress free life? I don't think we can. We just have to learn to walk away and do what is best for us - and our family.

PsA is associated with psoriasis. Have your C Reactive Protien levels checked, your Dr will get a better idea based on your results.